Heretofore, HARhTH has been prepared as its solution by adding silver oxide to a solution of hexaamminerhodium chloride to prepare a HARhTH solution and a precipitate of silver chloride, which precipitate was then removed by filtration. Similarly, HAPtTH has heretofore been prepared as its solution by adding silver oxide to a solution of hexaammineplatinum (IV) tetrachloride to prepare a HAPtTH solution and a precipitate of silver chloride, which precipitate was then removed by filtration. Likewise, TAPtDH has heretofore been prepared as its solution by adding silver oxide to a solution of tetraammineplatinum (II) dichloride to prepare a TAPtDH solution and a precipitate of silver chloride, which precipitate was then removed by filtration. Similarly, TAPDH has heretofore been prepared as its solution by adding silver oxide to a solution of tetraammine-palladium dichloride to prepare a TAPDH solution and a precipitate of silver chloride, which precipitate was then removed by filtration.
However, in each of the above described techniques, it was difficult to perform an equivalence reaction between the silver and the chloride ion to determine the amount of silver to be added. Consequently, excess silver was likely to remain in the product solution as an impurity.
Thus, there is a need in the art to provide a process of preparing a solution of each of the above noted compounds having reduced impurity levels. The present invention overcomes the above described disadvantages of the prior art.